Password Entropy
Calculate Password Entropy instantly with the exact formula and a worked example.
Password Entropy
Length
Alphabet size
Entropy
74.0391bits
More about: Password Entropy
What it calculates
The “Password Entropy” calculator computes Entropy in bits from 2 parameters: length, alphabet size.
Standard IT calculations for developers and sysadmins.
Example calculation
With parameters Length = 12, Alphabet size = 72 the result is 74.04 bits.
How to use
- Enter length and alphabet size — each field above is adjustable with a slider.
- Entropy (bits) is calculated automatically as you type.
- Check the worked example below to see the formula applied to real numbers.
- Copy the result or bookmark this calculator.
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FAQ
How is Password Entropy calculated?
The Password Entropy calculator computes Entropy (in bits) from length, alphabet size. Enter your values above and the exact formula is applied instantly; a worked example with real numbers is shown below.
Is the Password Entropy calculator free?
Yes. It is completely free, needs no signup, runs entirely in your browser, and sends no data to any server.
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